This document summarizes the nomenclature of enzymes involved in amino acid degradation. It discusses three types of organisms that catabolize amino acids: ammonotelic organisms that excrete ammonia, ureotelic organisms that excrete urea, and uricotelic organisms that excrete uric acid. The pathways for amino acid degradation and the urea cycle are described. Specific enzymes are named for each step using standardized nomenclature including EC numbers and systematic names. The roles of the liver and associated enzymes in removing nitrogen from amino acids and generating urea for excretion are also summarized.
structure of proteins
definition of Digestion
sources of Proteins --> EXOGENEOUS SOURCES 50-100g/day and ENDOGENEOUS SOURCES 30-100g/day
Proteins DEGRADED BY --> HYDROLASES specifically PEPTIDASES(ENDOPEPTIDASES & EXOPEPTIDASES)
1. Gastric Digestion of Proteins
2. Pancreatic Digestion of Proteins
3. Digestion of Proteins by Small Intestine Enzymes
Absorption of Amino ACids by Na+Dependent, Na+ Independent, Meister Cycle or gama-glutamyl cycle
Metabolism of amino acids (general metabolism)Ashok Katta
Metabolism of amino acids (general metabolism).
Part - I of amino acid metabolism.
This presentation covers Transamination, deamination, formation and Transport of Ammoniaand etc.
Digestion of proteins, absorption of amino acids, synthesis of amino acids, catabolism of amino acids and synthesis of specialised non-protein compounds from amino acids for undergraduates
structure of proteins
definition of Digestion
sources of Proteins --> EXOGENEOUS SOURCES 50-100g/day and ENDOGENEOUS SOURCES 30-100g/day
Proteins DEGRADED BY --> HYDROLASES specifically PEPTIDASES(ENDOPEPTIDASES & EXOPEPTIDASES)
1. Gastric Digestion of Proteins
2. Pancreatic Digestion of Proteins
3. Digestion of Proteins by Small Intestine Enzymes
Absorption of Amino ACids by Na+Dependent, Na+ Independent, Meister Cycle or gama-glutamyl cycle
Metabolism of amino acids (general metabolism)Ashok Katta
Metabolism of amino acids (general metabolism).
Part - I of amino acid metabolism.
This presentation covers Transamination, deamination, formation and Transport of Ammoniaand etc.
Digestion of proteins, absorption of amino acids, synthesis of amino acids, catabolism of amino acids and synthesis of specialised non-protein compounds from amino acids for undergraduates
these clearance test plays an very important role in determining the functioning capacity and working status of kidney.
and we estimate how amount of compund is excreted in the urine and absorption too.
and i also attached the mathematical caluculation to identify the metabolic valuve of urea, creatinine, inulin clearance by kidney.
Methionine metabolism
Activation of methionine and transmethylation
Conversion of methionine to cysteine
Degradation of cysteine.
Cysteine metabolism
Formation
Metabolic Function
Metabolism Disorders of Sulfur containing amino acid
these clearance test plays an very important role in determining the functioning capacity and working status of kidney.
and we estimate how amount of compund is excreted in the urine and absorption too.
and i also attached the mathematical caluculation to identify the metabolic valuve of urea, creatinine, inulin clearance by kidney.
Methionine metabolism
Activation of methionine and transmethylation
Conversion of methionine to cysteine
Degradation of cysteine.
Cysteine metabolism
Formation
Metabolic Function
Metabolism Disorders of Sulfur containing amino acid
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
3. INTRODUCTION
• Amino acids make a significant contribution to
the generation of metabolic energy.
• Carnivores can obtain up to 90% of their energy
requirements from amino acid oxidation,
whereas herbivores may fill only a small fraction
of their energy needs by this route.
• In plants, the purpose of amino acid catabolism
is to produce metabolites for other biosynthetic
pathways, rarely for energy.
4. Organisms witnessing amino acid
catabolism
I. Ammonotelic organisms – It includes most aquatic
vertebrates, such as bony fishes & the larvae of
amphibians who excrete it in the form of
ammonia (as ammonium ion).
II. Ureotelic organisms – It includes many terrestrial
vertebrates & also sharks who excrete it in form of
urea.
III. Uricotelic organisms – It includes birds, reptiles
who excrete it in form of uric acid.
5. Associated Pathway
1.
a) L-amino acids reach the liver.
b) The enzyme “aminotransferases or transaminases”
remove their α-amino group by transamination reactions
and transfer it to the α-carbon atom of α-ketoglutarate
leaving behind α-keto acid.
• ENZYME- Aminotransferases
• Prosthetic group- Pyridoxal phosphate
• E.C Number – 2.6.1.4
• The enzyme belongs to the class transferases.
• It transfers nitrogenous groups.
• It belongs to sub-sub class transaminases.
6. In hepatocytes, glutamate is transported from the
cytosol to mitochondria where it goes oxidative
deamination under the action of “L-glutamate
dehydrogenase” to yield α-ketoglutarate.
• ENZYME- L-Glutamate dehydrogenase
• E.C Number – 1.4.1.2
• Systematic name – L-glutamate:NAD+ oxidoreductase
• It belongs to class oxidoreductase.
• It acts on the CH-NH₂ group of donors.
• It has NAD or NADP as acceptor.
• It has been given a name glutamate dehydrogenase.
7. 2.
a) The free ammonia produced in tissues is combined with
glutamate under the action of another enzyme “glutamine
synthetase”.
b) This is because the toxic ammonia has to be converted into
a non-toxic compound before export into the blood.
c) Hence, ATP & glutamate react to form ADP and ү-glutamyl
phosphate(intermediate) which then reacts with ammonia
to produce glutamine & inorganic phosphate.
d) This glutamine is a non-toxic transport form of ammonia.
• ENZYME- Glutamine synthetase
• E.C Number- 6.3.1.2
• Systematic name – L-glutamate:ammonia ligase
• It belongs to ligase class.
• It forms carbon-nitrogen bonds.
• It belongs to sub-sub class acid-ammonia ligase.
8. 3.
a) Glutamine is now converted into Glutamate & NH₄⁺ under
the action of the enzyme Glutaminase.
b) The NH₄⁺ from intestine & kidney is transported in the
blood to the liver.
c) In the liver, the ammonia from all sources is disposed off by
urea synthesis.
• ENZYME – Glutaminase
• E.C Number – 3.5.1.2
• Systematic Name – L-Glutamine amidohydrolase.
• It is a hydrolase.
• It acts on carbon-nitrogen bonds other than peptide bonds.
• It acts on linear amides.
• It is named as Glutaminase.
• It always acts in the presence of an acceptor water molecule.
9. UREA CYCLE
1.
• Ammonia deposited in the mitochondria of
hepatocytes is required to be converted into urea.
• It spans two cellular compartments; mitochondria
of liver & the cytosol.
• The NH₄⁺ generated in the liver & CO₂ produced by
mitochondrial respiration forms ‘carbamoyl
phosphate’ in the matrix,catalayzed by ‘Carbamoyl
phosphate synthetase І’.
10. • Enzyme – Carbamoyl phosphate synthetase І.
• E.C Number – 6.3.4.16
• Systematic name- Hydrogen carbonate:ammonia ligase.
• It is a ligase.
• It forms carbon-nitrogen bonds.
• It is other carbon-nitrogen ligase.
• It is carbamoyl phosphate synthetase І.
11. 2.
a) The carbamoyl phosphate donates its carbamoyl
group to ornithine to form citrulline with the
release of Pi.
b) The enzyme catalyzing it is Ornithine
transcarbamoylase.
• ENZYME – Ornithine transcarbamoylase
• E.C Number – 2.1.3.3
• Systematic Name - Carbamoyl-phosphate:L-ornithine
carbamoyltransferase
• It is a transferase.
• It tranfers one-carbon groups.
• These are carboxy and carbamoyltransferses.
• It is named ornithine transcarbamoylase.
• The citrulline passes from the mitochondrion to the cytosol.
12.
13. 3.
a) A condensation reaction takes place between the
amino group of aspartate(generated in
mitochondria & transported into cytosol) and the
ureido (carbonyl) group of citrulline.
b) It leads to the formation of argininosuccinate.
c) It is catalyzed by argininosuccinate synthetase.
• ENZYME – Argininosuccinate synthetase
• E.C Number – 6.3.4.5
• Sytematic name – L-citrulline:L-aspartate ligase
• It is a ligase.
• It forms carbon-nitrogen bonds.
• It is other carbon-nitrogen ligase.
• Its name is argininosuccinate synthetase.
14. 4.
a) The argininosuccinate is then cleaved by the
enzyme argininosuccinase.
b) It forms free arginine & fumarate.
c) This fumarate enters mitochondria to participate
Kreb’s cycle.
• ENZYME – Argininosuccinase
• E.C Number – 4.3.2.1
• It is a lyase.
• It acts on carbon-nitrogen bonds.
• It acts on amides,amidines etc.
• It is arginosuccinate lyase.
15. 5.
a) Arginine is cleaved by the cytosolic enzyme
‘arginase’.
b) It yields urea & ornithine.
c) This ornithine is transported into the mitochondria
to start another round of urea cycle.
• ENZYME – Arginase
• E.C Number – 3.5.3.1
• Systematic name – L-arginine:amidino hydrolase
• It is a hydrolase.
• It acts on carbon-nitrogen bonds.
• It acts on other than peptide bonds in linear
amidines.
• It is arginase.
16. CONCLUSION
• The liver is the major site of degradation for most
amino acids.All amino acids contain atleast one
nitrogen atom,which forms their α-amino group.
• Nitrogen is removed from the carbon skeleton and
transferred to α-ketoglutarate , which yields glutamate.
• The carbon skeletons are converted to intermediates of
the mainstream carbon oxidation pathways.
• Surplus nitrogen is removed from
glutamate,incorporated into urea,and excreted.